It is easy to use After Effects as a virtual camera that will simulate complex navigation across a flat piece of artwork in a way that mirrors the animation stand “moves” used in traditional filmmaking. All the techniques talked about in the preceding chapter on kinestasis and collage animation can be achieved faster, cheaper, and with more accuracy by using After Effects by referring to familiar film technology.
Pans. When shooting film, you create pans by moving the camera or the animation stand frame to give the feeling of moving across still image. To create a pan in After Effects, you simply move artwork left, right, up or down in the program’s composition window. You tell the computer where you want your pan to start and stop by setting key frames at your start and finish points.
Zooming. In film, zooming in is achieved by changing the distance, frame by frame, between the camera and your artwork. In After Effects, you can simulate a zoom by scaling or resizing your artwork over time.
Fades. Traditionally, in-camera fades are made by slowly adjusting the amount of light coming through the lens aperture. To fade out (to black) you close the lens down over, say, 24 successive frames. To fade in (from black) on the new piece of artwork, that process is reversed. In After Effects you can fade in and fade out by manipulating key frames. Think of key frames as markers of precise moments when a selected image will be manipulated in one way or another. When making fades, a first key frame marks the moment when the computer will begin to adjust the opacity levels. If an image is set at an opacity of 0 percent, then it is not opaque at all. In other words, you can see through it. If an image has an opacity of 100 percent, then it is fully opaque and cannot be seen through at all. It follows, then, that if you cent opacity all the way to 100 percent opacity, the resulting effect will be that of watching an image go from being perfectly transparent (clear) to being completely opaque (solid) in the amount of time you have designated by choosing two key frames. In After Effects, 0 percent to 100 percent opacity appears in fade-up from black – because the black background (a default setting) will show through your image when it is not fully opaque. To the viewer’s eye this looks exactly like a fade-up from black in traditional filmmaking.
Laybourne, K., 1998. The Animation Book. New York: Three Rivers Press